The present invention is related to a coupling for use with a hose. Specifically, the present invention is related to the configuration of the coupling assembly wherein the coupling is provided with means to compensate for the flow characteristics of a hose end during crimping of the coupling.
During testing of a fitting formed out of a low strength material, it was discovered that the force generated from crimping the ferrule onto a fitting or coupling shank actually destroyed the shank of the fitting. The hose being crimped produces enough force on the ferrule interlock to push the interlock groove apart on the fitting itself. During crimping, the hose material between the fitting and the ferrule tends to extrude in both directions, creating the problem. Although this extrusion condition exists when crimping hoses onto higher strength fitting materials, the coupling material has adequate strength to prevent movement of the interlock groove.
FIG. 12 illustrates a prior art fitting. Other typical fittings are disclosed in U.S. Pat. Nos. 5,370,425, 4,548,430, 4,522,435, and 3,539,207. The particular illustrated fitting 100 is a male coupling unit of a cam and groove coupling assembly; however, the particular type of assembly in which the fitting is to be employed in is irrelevant for this invention. The stem portion 102 of the fitting 100 is for insertion into a hose 110, see FIG. 13. The stem 102 is characterized by a series of barbs 104 for interacting with the inside of the hose 110 and gripping the hose 110 after a ferrule 112 is crimped onto the stem 102. Adjacent to the series of barbs 104 is an interlock shoulder 106 and an interlock groove 108. The ferrule 112 is placed over the stem 102 and hose 110 such that the interlock shoulder 116 of the ferrule 112 is aligned with the interlock groove 108 of the stem 102. The stem 102 is inserted into the hose 110 until the hose end 114 abuts against the interlock shoulder 106. As discussed above, during crimping of the ferrule 112 onto the hose 110 and stem 102, the pressure forces the hose 110 to extrude in both directions, see FIG. 14. In one direction, the hose 110 extrudes towards, and between, the hose barbs 104, a desired effect assisting in creating a secured attachment. In the other direction, the hose 110 extrudes toward the interlock shoulder 106, an undesired effect that exerts pressure on the interlock shoulder 106, and forces the interlock shoulder 106 toward the ferrule interlock groove 108, and can damage the ferrule interlock shoulder 116, the stem interlock shoulder 106, and the ferrule interlock groove 108, potentially compromising the crimping.
Other fittings have structures which attempt to overcome this problem, for example see U.S. Pat. No. 4,198,079, GB 2165909, DE 4401672. U.S. Pat. No. 4,198,079 obviates the problem by not securing the hose end, permitting the hose to extrude outwardly as the assembly is crimped. GB 2165909 discloses an annular space 35 within the ferrule into which the hose may be extruded as the assembly is crimped. DE 4401672 discloses a stem wherein the groove adjacent to the shoulder against which the hose abuts has a slightly greater depth than the adjacent grooves between the stem barbs.
However, with the assembly of U.S. Pat. No. 4,198,079, the end of the hose may become damaged during use. Concerning the teachings of GB 2165909, the use of a standard ferrule with the assembly is precluded, and can increase the cost of the assembly. The space provided by DE 4401672 might be insufficient to permit the hose material to extrude and can place pressure onto the stem and ferrule, compromising the assembly.
The present invention is directed toward a fitting constructed so as to prevent possible damage to the fitting during crimping of the hose onto the fitting shank.
The present invention is directed towards an improved fitting for insertion in a hose. The fitting is comprised of an interlock shoulder on the fitting designed to abut an end of the hose and a groove in the body of the fitting, adjacent to the shoulder, for receiving the shoulder of a ferrule when the hose is secured to the fitting by crimping the ferrule in a radially inward direction. The improvement to fitting is characterized by the shoulder having an extension against which the hose abuts prior to crimping. The extension has a recess into which material of the hose can extrude during crimping of the hose.
In another aspect of the invention, the extension of the improved fitting is continuous about the circumference of the fitting. The extension may also be discontinuous about the circumference of the fitting, forming a plurality of extensions about the fitting.
The recesses formed in conjunction with the extensions may be located radially inward of the extension or adjacent to the extensions, the recesses thereby separating the extensions.